FIG. 1 shows a block diagram of a conventional semiconductor device 100 including a temperature sensor 150. The conventional semiconductor device (or, a semiconductor chip) 100 includes a plurality of banks 110, 120, 130 and 140, the temperature sensor 150, and a controller 160.
Each of the plurality of banks 110, 120, 130 and 140 may operate independently. For example, the banks 130 and 140 operate while the banks 110, 120 do not. In such instance, the temperature of the area surrounding the banks 130 and 140 is higher than the temperature of the area surrounding the banks 110 and 120. However, when the temperature sensor 150 is capable of sensing a temperature only for the area surrounding the bank 110, the temperature of the area surrounding banks 130 and 140 is not measured correctly.
If the temperature of the area surrounding the bank 110 is lower than 45° C., the controller 160 outputs a self-refresh signal with a period of 420 ms to each of the plurality of banks 110, 120, 130 and 140 in response to an output signal of the temperature sensor 150. If the temperature of the area surrounding the bank 110 is higher than 45° C., the controller 160 outputs a self-refresh signal with a period of 140 ms to each of the plurality of banks 110, 120, 130 and 140.
If the temperature of the area surrounding the bank 140 is higher than 50° C. due to the operation of the bank 140, and the temperature of the area surrounding the bank 110 is lower than 40° C. due to non-operation of the bank 110, the temperature sensor 150 cannot sense the temperature of the area surrounding the bank 140. Thus, the controller 160 outputs the self-refresh signal with a period of 420 ms as a result of the lower temperature of the area surrounding the bank 110. Since the controller 160 outputs the self-refresh signal with a period of 420 ms to each of the plurality of banks 110, 120, 130 and 140, data to be input to or output from the bank 140 can fail.